1. Field
The present application relates generally to the distribution of data over a data network, and more particularly, to methods and apparatus for dynamic packet mapping.
2. Background
Data networks, such as wireless communication networks, have to trade off between services customized for a single terminal and services provided to a large number of terminals. For example, the distribution of multimedia content to a large number of resource limited portable devices (subscribers) is a complicated problem. Therefore, it is very important for network administrators, content retailers, and service providers to have a way to distribute content and/or other network services in a fast and efficient manner for presentation on networked devices.
In current content delivery/media distribution systems, real time and non real time services are packed into a transmission frame and delivered to devices on a network. For example, a communication network may utilize Orthogonal Frequency Division Multiplexing (OFDM) to provide communications between a network server and one or more mobile devices. This technology provides a transmission frame having data slots that are packed with services to be delivered over a distribution network.
Typically, data representing one or more services is rate adjusted and processed using one or more error correction techniques. For example, the data may be turbo encoded, bit interleaved, and then divided into slots that are bit scrambled. Additionally, constellation mapping and symbol interleaving may be performed. Finally, the data may be mapped into interlaces to form an OFDM symbol.
At a receiving device, the above processes need to be reversed in order to obtain data packets that can be decoded to recover the transmitted services. This requires that detected packets be mapped so that they can be associated with the appropriate logical channel. Unfortunately, conventional systems may reverse the above processes in a step by step manner utilizing intermediate memories. This is especially true of the mapping process in which the size of the memories may greatly increase based on the number of logical channels thereby increasing processing latencies.
Therefore what is needed is a system to process data in a received transmission frame so that decodable packets for each logical channel can be obtained in a memory efficient manner, thereby minimizing processing latencies.